monty that depends what you are viewing your digital photo in.. I mean what software. Some are view only others will manipulate. I have paintshop pro, not cheap but wonderful, I know others have different views, some digital photography monthlies have free stuff on the cover. Its not the border you need, its the means of applying it
At a pinch, you could use the ordinary Paint program that comes with Windows. Just open a new project, set the size slightly larger than your photo, and paint it to the colour that you want your border to be. Then simply paste your photo into the middle and you have a border around the photo.
Just learned you have Paintshop, from another Q. Open your image and shift to Image Ready, click select/all then select/modify/border. Then use the paintbucket to paint the border to any colour or effect that you want. To make an ornate frame, use the border option 3 or 4 times with different attributes.